Lack of sleep effects

By Dr Simon Kyle

It is perfectly normal to worry about the effects of a lack of sleep. In fact, the findings of the Great British Sleep Survey tell us that 68% of poor sleepers surveyed were bothered by thoughts about how they would cope the next day.

It stands to reason that these worries may not be completely unfounded and years of research on good sleepers has shown that, although the effects of sleep deprivation vary by person, we are all affected following a night of insufficient or poor sleep. Just some of the areas in which you may be affected are mood and emotional processing, pain thresholds, functioning of the immune system and glucose metabolism.

Lack of sleep and sport

Research into how lack of sleep affects sports performance, further emphasizes the potential impact of sleep deprivation. In particular, impairments to glucose metabolism may prove problematic for athletes who rely on their energy supplies to perform to the best of their ability. In fact, athletes may benefit from even more sleep than the average person; a recent study found that collegiate basketball players saw their performance improve significantly after sleeping for at least 10 hours (Mah et al. 2011).

Lack of sleep and health

Effects of sleep deprivation on the skin should not be overlooked either. A lack of sleep can impair the body's ability to fend off diseases (Irwin et al. 1994) and inflammation. One recent study on rats showed that partial sleep deprivation led to worsening of psoriasis-related biomarkers thus possibly increasing the risk of the subject developing psoriasis (Hirotsu et al., 2012).

Finally, a chronic lack of sleep has also been linked to weight gain. A study by Spiegel et al. (2004) found that restricting sleep in 12 healthy men for two days, from 10 to 4 hours, resulted in a reduction in leptin (a hormone involved in feeling 'full' after eating) and elevations in ghrelin (hormone involved in stimulating feelings of hunger). These hormonal changes were also accompanied by self-reported increases in appetite and hunger, particularly for high calorie foods.

Alongside this, simply being awake longer and at odd times may, for example, give us more opportunity to eat and limit our ability and motivation to exercise!

How bad are the effects of a lack of sleep?

However, the good news is that the effects of a lack of sleep may not be as bad as one would expect. How refreshed you feel in the morning will depend both on the continuity and architecture of sleep. We know that the first few hours of sleep are the most beneficial, in terms of physical restoration, which is why one will sometimes wake up after 3 hours of sleep and feel well rested. It is the exclusion of certain sleep stages that was linked to many of the negative effects of sleep deprivation discussed.

Fortunately, we do not need to repay sleep loss on an hour-for-hour basis. The best evidence we have from experimental studies of sleep deprivation suggests that we need to make up less than one-third of our lost hours. Furthermore, the sleep we get on recovery nights may be deeper and more restorative.